Waveguide Display with Multiple Monochromatic Projectors

2. The waveguide display of claim 1, wherein the one or more first middle gratings include three first middle gratings, each first middle grating of the three first middle gratings corresponding to a respective input grating of the three non-overlapping input gratings and configured to receive and redirect the display light of the respective color from the corresponding respective input grating.

5. The waveguide display of claim 4, wherein each projector of the three projectors includes a two-dimensional array of micro-LEDs.

6. The waveguide display of claim 1, further comprising a phase structure on the waveguide, the phase structure configured to change a polarization state of the display light incident on the phase structure before or after the display light is redirected by the one or more first middle gratings.

7. The waveguide display of claim 6, wherein the phase structure comprises a waveplate, a layer of a birefringent material, or a subwavelength structure and an overcoat layer.

8. The waveguide display of claim 6, wherein the phase structure is in selected regions of the waveguide or is characterized by a spatially varying phase retardation across different regions of the phase structure.

9. The waveguide display of claim 1, wherein the three non-overlapping input gratings, the one or more first middle gratings, and the second middle grating include multiplexed transmissive volume Bragg gratings or multiplexed reflective volume Bragg gratings.

12. The waveguide display of claim 10, wherein the respective staircase structure is characterized by a total thickness less than 100 μm.

13. The waveguide display of claim 10, wherein the respective staircase structure includes two or more holographic material layers, the input grating formed in the two or more holographic material layers.

14. The waveguide display of claim 10, wherein a shape and a thickness of the respective staircase structure are selected to avoid clipping of a field of view of the waveguide display by the respective staircase structure.

17. The waveguide display of claim 15, further comprising a phase structure on the waveguide, the phase structure configured to change a polarization state of the display light incident on the phase structure after or before the display light is diffracted by the three first middle gratings.

18. The waveguide display of claim 17, wherein the phase structure comprises a waveplate, a layer of a birefringent material, or a subwavelength structure and an overcoat layer.